Bronchiolitis is a common viral lower respiratory tract infection primarily affecting infants and young children under 2 years of age. It is most common during autumn and winter.

Causative Agent: Respiratory Syncytial Virus (RSV), others include rhinovirus, coronavirus, adenovirus, and parainfluenza.

The condition is typically mild and self-limited but can sometimes progress to respiratory failure. Management is supportive, with hydration and oxygen, as no specific medications treat the infection.

Risk Factors

  • Age <2 Years, severe in less than 3 months
  • Premature baby and Low birth weight
  • Formulafed
  • Congenital heart disease
  • Airway anomalies
  • Congenital immune deficiency disorders
  • Dust and smoke exposure, parental smoking
  • Crowded living environment
  • Low socioeconomic population

Pathophysiology

  • Bronchiolitis is primarily due to airway obstruction and diminished lung compliance.
  • The virus infects epithelial cells in the airways, inducing an inflammatory reaction that leads to ciliary dysfunction and cell death.
  • Accumulated debris,buildup mucus, airway edema, and narrowing due to cytokine release lead to partial bronchiole obstruction (lead to air trapping) or complete obstruction (causing atelectasis) and lowered lung compliance.
  • The body tries to overcome the decreased compliance by breathing harder.

Clinical Features

Symptoms Signs
  • Cough
  • Wheezing
  • Fast breathing
  • Nasal congestion
  • Irritability
  • Poor feeding
  • Fever
  • Tachypnea
  • Subcostal retractions
  • Nasal flaring
  • Crackles and wheezes on auscultation
  • Cyanosis (in severe cases)

The course of the illness may last 7 to 10 days, and the infant may become irritable and avoid feeding. However, most infants improve within 14 to 21 days, as long as they are well hydrated.

Differential Diagnosis (D/D) & Complications

D/DComplications
  • Asthma
  • Pneumonia
  • Foreign body aspiration
  • Congenital heart disease

 
  • Respiratory failure
  • Apnea
  • Dehydration
  • Secondary bacterial infection

Investigation

  • Chest X-ray
bronchiolitis x-ray fetures

X-ray finding

  • Hyperinflated lung field (Ribs shadow >7)
  • Peribronchial thickening in perihilar regions
  • Air trapping
  • Atelectasis

Admission Criteria

  • Age less than 12 weeks
  • Severe respiratory distress (RR: >60 and <80), increased work of breathing
  • Apnea
  • Hypoxia (SpO2 < 90%)
  • Inability to maintain hydration or unable to feed
  • High risk: prematurity, neonates, chronic lung or heart disease, immunodeficiency

Management

Emergency Management:

  • Assess Airway, Breathing, and Circulation
  • Monitor SpO2
  • Administer supplemental oxygen if needed
  • Assess hydration
  • Provide supportive care (Antipyretic, 3% NS nebulization)

Outpatient:

  • Paracetamol
  • Normal saline nasal drops
  • Add antibiotics if chest x-ray shows infiltration
    • Syp Azithromycin for 5 days or Drop Amoxicillin for 5 days

Rx:

  1. Drop Amoxicillin x TDS x 7 days or Syp Azithromycin PO x OD x 5 days
  2. Syp LCTZ or Syp Fexofenadine for cough PO BD or HS x 5 days
  3. Syp/Drop PCM PO TDS x 3 Days then SOS
  4. NS Nasal Drop 2 Drops Both Nose x 2hourly or 4 hourly x 2 days then SOS

Inpatient:

  • Admit or refer all patients who meet admission criteria
  • O2 via nasal prong
  • Bubble CPAP or intubation if severe respiratory present
  • Treatment:
    • Inj Ampiclox (If bronchiolitis with secondary chest infection)
    • Inj PCM (Paracetamol)
    • Normal saline nasal drops
    • 3% NS nebulization QID
    • Fluid therapy to maintain hydration
    • Chest physiotherapy
  • NPO if the child is in severe respiratory distress; supervised feeding can be tried if not in severe distress.

Rx:

  1. Inj Amoxicillin IV BD x 7 Days (Add Inj Amikacin if baby is in severe respiratory distress)
  2. Syp LCTZ or Syp Fexofenadine PO BD or HS x 5 days (If tolerated)
  3. Syp/Drop PCM PO TDS x 3 Days then SOS
  4. NS Nasal Drop 2 Drops Both Nose x 2hourly or 4 hourly x 2 days then SOS
  5. 3% NS Nebulization QID or TDS or Asthalin Nebulization (If wheeze present) TDS or BD
  6. Fluid Therapy According to Age
  7. O2 suplement via facemask, nasal prong
  8. May need BCPAP or ventilation if severe respiratory distress present

Advices:

  • Encourage parents to maintain hydration and monitor the child closely
  • Explain danger signs (bluish discoloration of the skin, chest retraction, poor feeding, irritability)
  • Educate parents about the signs of worsening respiratory distress and when to seek emergency care
  • Avoid dust, smoke, and cold exposure
  • Flu vaccine if the child is more than 6 months old with a history of recurrent respiratory infection

Referral

  • Refer the child to a higher center if the child has severe respiratory distress, apnea, or requires intensive care

Follow-up

  • Schedule a follow-up appointment in 1-2 weeks to assess recovery and monitor for any complications

References:

  1. Ralston SL, Lieberthal AS, Meissner HC, et al. Clinical Practice Guideline: The Diagnosis, Management, and Prevention of Bronchiolitis. Pediatrics. 2014;134(5):e1474-e1502.
  2. Lukšić I, Kearns PK, Scott F, et al. Targeting the viral genome: impact of a DNA binding drug on bronchiolitis severity and duration. J Antimicrob Chemother. 2015;70(7):2057-2062.